Reusable drinking containers that can be sealed for traveling or storage are well known in the art, and are frequently used for carrying liquids for sporting activities such as bicycling, hiking, boating and camping. Such containers are increasingly used by spectators of sporting events, families with small children, and in fact by anyone who desires to keep drinkable beverages handy. For these types of activities, it is desirable to be able to drink directly from the container, as the provision of a separate cup provides additional complications of storage of the cups, transfer of the liquid from the container to the cup, and either disposal of the cups with their residue of the beverage, or storage and transport of the possibly wet and dripping cups until they can be cleaned and dried.
For many of these containers, a threaded cap is provided that can be removed to fill the container or to pour liquids from the container, some having an additional element in the center of the cap having a smaller opening for transferring the liquid directly to the mouth of the user. A push-pull cap is frequently provided for this purpose comprising a sliding dispensing top with a central opening, and a stem configured such that it plugs the opening when the sliding top is depressed and allows liquid to flow through the opening when the sliding top is extended, U.S. Pat. Nos. 5,104,008 and 6,874,664 appear to show such push-pull caps.
Designs of this sort require that the head of the user be tilted back and the container overturned and held nearly vertical over the user's mouth for efficient dispensing of the beverage into the mouth. Such a posture is difficult for small children, may cause spectators to miss portions of the event or action due to averting the eyes to drink, and could be dangerous for bikers, hikers, or boaters by causing changes in posture and field of vision which could cause loss of control or accident. To address this problem, some containers are provided with straws having an internal opening at or near the bottom of the volume of liquid and an external opening above the top of the container through which the user can suck the liquid while the container and the user's head remain upright. U.S. Pat. Nos. 7,516,862 and 4,448,316, and 4,607,755 appear to provide this feature.
A further limitation of these containers is that the empty containers occupy as much volume as the full containers. In many cases it is desirable that the containers be collapsible, so that when beverages are no longer being stored, the volume of the container can be decreased and the empty containers packed into a smaller space, for example, for shipping, disposal, or storage. Several, designs of such collapsible containers exist, either having container walls made of flexible material as appears to be provided in U.S. Pat. No. 3,604,491, or incorporating corrugated or “bellows” structures which are designed to collapse along a particular geometry as in U.S. Pat. No. 4,790,361. The addition of a conventional straw to such a container makes collapsing the container more difficult, because the rigid walls of the straw either prevent the bottle from collapsing or kink when folded, making the straw unusable.
In conventional reusable containers, only one opening into the container is provided, and necessarily represents a compromise between ease of filling the container and dispensing from the container, ease of accessing the container for cleaning, and perhaps most importantly, ease of manufacture. The opening is usually sealed with a threaded cap. The threaded openings must typically be manufactured to relatively high tolerances to form a tight seal, and larger openings usually require heavier or more rigid plastics and more expensive manufacturing processes to achieve these tolerances. Consequently, the openings of the containers are usually relatively small, less than an inch across for a normal 8 to 16 ounce container. The small size of the threaded opening typically limits the insertion of cleaning devices such as sponges or brushes required to thoroughly clean such a container, and may leave certain parts of the container such as the inside of the upper shoulder inaccessible for cleaning. Alternative configurations are available in which the opening occupies most of the width of the container which makes them easier to clean, but pouring liquids from a bottle with such a large opening requires more care to avoid spillage, and manufacturing an opening of that size that will reliably seal requires the use of more rigid or thicker materials and tighter tolerances in manufacture.
For collapsible containers, especially those with flexible walls, there is an additional difficulty in unscrewing a cap because the flexible material being held in one hand distorts due to the force applied by the other hand to remove the cap. This difficulty increases dramatically with an increase in the size of the cap, because the twisting force, which can be thought of as opposite forces applied to opposite sides of the cap across the diameter of the cap creating a torque, increases as the diameter of the cap increases.
Accordingly, there is a need for a collapsible container from which a user can drink while the container and the user's head are in a substantially upright position, which can be conveniently filled and from which liquids can conveniently be poured, and which can be fully opened for cleaning. There is a further need for all openings into such a container to be independently and reversibly sealed.